Search

The aim of this work was to investigate the possible origin of local Brazilian pig breeds through Cytochrome b (MT-CYB) mitochondrial analyses. The results indicated that the main local pig breeds descended from two different European maternal lineages, both Iberian varieties. The haplotype relationship analysis showed that Monteiro, Nilo, Piau and Tatu breeds share haplotypes only with Iberian varieties, while the Moura breed presented a different maternal lineage. The Moura appears to share a high frequency of haplotypes with the Black Hairy Iberian variety and Hungarian Mangalica breed.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:08:05Z No. of bitstreams: 0 Made available in DSpace on 2013-08-22T19:08:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-08-01 Made available in DSpace on 2013-09-30T18:28:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-08-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:41:29Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T13:41:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-08-01 O experimento teve como objetivo verificar a ação da apramicina (10 ppm) e dos ácidos fórmico + propiônico (0,0; 0,1 e 0,2%) no desempenho de frangos de corte sexados. A mistura dos ácidos orgânicos foi de 1:1. O delineamento foi inteiramente casualizado, em esquema fatorial 2 x 3 x 2 (apramicina x ácidos orgânicos x sexos), com 4 repetições de 45 aves por parcela, totalizando 2.160 pintos Cobb de 1 dia. As aves receberam ração à vontade. Na fase inicial, a adição da apramicina (10 ppm) e 0,1% dos ácidos orgânicos, isoladamente, melhorou o ganho de peso das aves. A adição conjunta dos produtos não promoveu ganho acumulado. Na presença da apramicina, a adição dos ácidos orgânicos piorou a conversão alimentar. Nas fases final e total, os dados de desempenho não apresentaram diferenças significativas. O rendimento de carcaça foi prejudicado com a adição conjunta da apramicina e 0,1% dos ácidos orgânicos. A trial was carried out to study isolated or combined effect of Apramicin (10ppm) and formic + propionic acids (0.0; 0.1 and 0.2%) supplementation in broilers diets. Acids mixtures were blended in a 1:1 ratio. A completely randomized design was utilized in a 2 x 3 x 2 factorial scheme (apramicim x organic acids x sex) with 4 replicates of 45 birds per experimental unit, with 2160-day-old Cobb chicks. Birds were fed ad libitum. In the initial phase, the supplementation of apramicin and organic acids (0.1%) alone, increased (p

Origin-dependent replication of the herpes simplex virus type 1 genome requires the virally encoded origin-binding protein, UL9. UL9 binds specifically to the herpes simplex virus type 1 replication origin at two high affinity binding sites on the DNA, Boxes I and II. UL9 also has ATP-dependent DNA helicase and DNA-stimulated ATPase activities that are used to unwind the origin DNA. Origin-specific binding is mediated by the C-terminal domain (C-domain) of the enzyme. ATPase and helicase activities are mediated by the N-terminal domain (N-domain). Previous studies have shown that single-stranded DNA is a good coeffector for ATPase activity. We have analyzed several DNAs for their ability to stimulate the ATPase activity of UL9 and of a truncated UL9 protein (UL9/N) consisting only of the N-domain. We report here that duplex Box I DNA specifically and potently stimulates the ATPase activity of UL9 but not of UL9/N. We also find that removal of the C-domain significantly increases the ATPase activity of UL9. We have incorporated these results into a model for initiation in which the C-domain of UL9 serves to regulate the enzymatic activity of the N-domain.

Predictions of tertiary structures of proteins from their amino acid sequences are facilitated greatly when the structures of homologous proteins are known. On this basis, structural features of Escherichia coli ornithine transcarbamoylase (OTCase) were investigated by site-directed mutagenesis experiments based on the known tertiary structure of the catalytic (c) chain of E. coli aspartate transcarbamoylase (ATCase). In ATCase, each c chain is composed of two globular domains connected by two interdomain helices, one of which is near the C-terminus and is critical for the in vivo folding of the chains and their assembly into trimers. Each active site is located at the interface between two chains and requires the participation of residues from each of the adjacent chains. OTCase, a trimeric enzyme, has been proposed to be similar in structure to the ATCase trimer on the basis of sequence identity (32%), the nature of the reaction catalyzed by the enzyme, and secondary structure predictions. As shown here, analysis of OTCase and ATCase sequences revealed extensive evolutionary conservation in portions corresponding to the ATCase active site and the C-terminal helix. Truncations and substitutions within the predicted C-terminal helix of OTCase had effects on activity and thermal stability strikingly similar to those caused by analogous alterations in ATCase. Similarly, substitutions at either of two conserved residues, Ser 55 and Lys 86, in the proposed active site of OTCase had deleterious effects parallel to those caused by the analogous ATCase substitutions. Hybrid trimers comprised of chains from both these relatively inactive OTCase mutants exhibited dramatically increased activity, as predicted for shared active sites located at the chain interfaces. These results strongly support the hypothesis that the tertiary and quaternary structures of the two enzymes are similar.

Each catalytic (c) polypeptide chain of Escherichia coli aspartate transcarbamoylase (ATCase) is composed of two globular domains connected by two interdomain helices. Helix 12, near the C-terminus, extends from the second domain back through the first domain, bringing the two termini close together. This helix is of critical importance for the assembly of a stable enzyme. The trimeric E. coli enzyme ornithine transcarbamoylase (OTCase) is proposed to be similar in tertiary and quaternary structure to the ATCase trimer and has a predicted alpha-helical segment near its C-terminus. In our companion paper, we have shown that this putative helix is essential for OTCase folding and assembly (Murata L, Schachman HK, 1996, Protein Sci 5:709-718). Here, the similarity between OTCase and the ATCase trimer, which are 32% identical in sequence, was tested further by the construction of several chimeras in which various structural elements were switched between the enzymes by genetic techniques. These elements included the two globular domains and regions containing the C-terminal helices. In contrast to results reported previously (Houghton J, O'Donovan G, Wild J, 1989, Nature 338:172-174), none of the chimeric proteins exhibited in vivo activity and all were insoluble when overexpressed. Attempts to make hybrid trimers composed of c chains from ATCase and OTCase were also unsuccessful. These results underscore the complexities of specific intrachain and interchain side-chain interactions required to maintain tertiary and quaternary structures in these enzymes.

Isolated rat liver mitochondria, freed from microsomes and lysosomes contaminants, were maintained at 0-4 degrees C for several days using an appropriate medium and energy source. It was observed that the phospholipase A2 activity of mitochondria deficient in vitamin E is higher than in normal mitochondria, and that the presence of vitamin E in the preservation medium diminishes the phospholipase A2 activity in deficient mitochondria. In vitamin E deficient mitochondria up to 45% of phospholipids was digested by the endogenous phospholipase with little loss in the energy linked function or without considerable activation of the latent enzymes monoamine oxidase and ATPase. These results are consistent with the occurrence of phospholipids in the mitochondrial membrane which would render it more accessible to the action of phospholipase A2.

1. Cat retinal ganglion cells projecting to the superior colliculus (SC) were detected in flat whole-mounts of Nissl-stained retinas by means of unilateral intracollicular injections of horseradish peroxidase (HRP). 2. With the purpose of drawing a comparison between HRP-labeled ganglion cells and the remaining population of unlabeled ganglion cells, the latter were classified according to their perikaryal characteristics into three groups: large, medium and small ganglion cells. Measurements of perikaryal sizes of ganglion cells distributed from the central area to the periphery of the retina showed that large cells ranged from 20 to 44 μm, medium cells from 15 to 30 μm and small cells from 8 to 17 μm. 3. Peroxidase-labeled retinal ganglion cells (HRP-cells) occurred among representatives of each of the three groups into which retinal ganglion cells had been classified. Small HRP-cells clearly constituted the majority of the HRP-cell population. When the injection site was restricted to the superior colliculus, medium HRP-cells as large as 19 μm were only occasionally observed, the 15 to 18 μm range being predominant over the medium cell population. 4. Medium HRP-cells larger than 20 μm were a common finding only when the injection site involved the pretectal nuclei and were never observed when the injection site was restricted to superior colliculus. 5. Possibility of a correspondence between the large, medium and small HRP-cells of the present study with, respectively, the physiological types Y-, X- and W- of cat retinal ganglion cells is discussed.